1. Technical Field
The present disclosure relates generally to the field of information handling systems. More specifically, but without limitation, the present disclosure relates to data storage.
2. Background Information
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is an information handling system. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for such systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
In some circumstances, an information handling system (IHS) may save or store data or information and may need to provide fast access to the data. Some information handling systems use a data storage system such as a redundant array of independent/inexpensive disks/drives (RAID) to provide access to data and to provide data redundancy to the users of the data. Several different types of RAID arrays exist (e.g., RAID 1-6) and each type provides a different level of data access speed and/or data redundancy.
One type of RAID array is a RAID 1 array. A RAID 1 array may contain two disk drives for storing information. In accordance with a standard RAID 1 array, the same data may be written on both disks when data is stored to a RAID 1 array. This is commonly referred to as mirroring data. By mirroring data, a RAID 1 array provides a single level of redundancy such that if a failure occurs within one of the RAID 1 drives, data can still be recovered from the other non-failed drive. The non-failed drive may be used to rebuild the failed drive after a replacement disk drive has been inserted into the RAID 1 array. However, if both disks within the RAID 1 array fail, data cannot be recovered from a RAID 1 array.
Another type of RAID array is a RAID 5 array. A RAID 5 array contains at least three disk drives. A RAID 5 array may calculate a parity value for data which is to be written to the RAID 5 array. Furthermore, a RAID 5 array may stripe the data across multiple drives (store portions or blocks of a single file on multiple drives within the RAID 5 array) and store the parity value on a separate drive than the data. In the event a disk fails in a RAID 5 array, the parity values and data values on the non-failed disks may be used to rebuild the failed drive after a replacement disk has been inserted into the RAID 5 array. However, similar to a RAID 1 array data cannot be recovered if two disk drives within a RAID 5 array fail.
Consequently, a need exists to provide data recovery from a failure of two disks in a RAID 1 array or from a failure of two disks in a RAID 5 array.